scholarly journals Spatial and Temporal Characteristic Analysis of Imbalance Usage in the Hangzhou Public Bicycle System

2021 ◽  
Vol 10 (10) ◽  
pp. 637
Author(s):  
Xiaoyi Zhang ◽  
Yurong Chen ◽  
Yang Zhong
Keyword(s):  
Nearest Neighbor ◽  
Average Distance ◽  
Temporal Characteristic ◽  
Service Level ◽  
Spatial Filter ◽  
Walking Distance ◽  
Characteristic Analysis ◽  
Face To Face ◽  
Bike Sharing ◽  
Areas Of Interest

Calculating the availability of bicycles and racks is a traditional method for detecting imbalance usage in a public bicycle system (PBS). However, for bike-sharing systems in Asian countries, which have compact layouts and larger system scales, an alternative docking station may be found within walking distance. In this paper, we proposed a synthetic and spatial-explicit approach to discover the imbalance usage by using the Hangzhou public bicycle system as an example. A spatial filter was used to remove the false-alarm docking stations and to obtain true imbalance areas of interest (AOI), where the system operation department installs more stations or increases the capacity of existing stations. In addition, sub-nearest neighbor analysis was adopted to determine the average distance between stations, resulting in an average station spacing of 190 m rather than 15.5 m, which can reflect the nonbiased service level of Hangzhou’s public bicycle systems. Our study shows that neighboring stations are taken into account when analyzing PBSs that use a staggered or face-to-face layout, and our method can reduce the number of problematic stations that need to be reallocated by about 92.81%.

Temporal Changes in Habitat Selection and Nest Spacing in a Colony of Ross' and Lesser Snow Geese

The Auk ◽  
1983 ◽  
Vol 100 (2) ◽  
pp. 335-343 ◽  
Author(s):  
M. Robert McLandress
Keyword(s):  
Nearest Neighbor ◽  
Average Distance ◽  
Habitat Preferences ◽  
Nearest Neighbors ◽  
Nest Density ◽  
Snow Goose ◽  
Snow Geese ◽  
Lesser Snow Geese ◽  
Average Size ◽  
Island Habitats

Abstract I studied the nesting colony of Ross' Geese (Chen rossii) and Lesser Snow Geese (C. caerulescens caerulescens) at Karrak Lake in the central Arctic of Canada in the summer of 1976. Related studies indicated that this colony had grown from 18,000 birds in 1966-1968 to 54,500 birds in 1976. In 1976, geese nested on islands that were used in the late 1960's and on an island and mainland sites that were previously unoccupied. Average nest density in 1976 was three-fold greater than in the late 1960's. Consequently, the average distance to nearest neighbors of Ross' Geese in 1976 was half the average distance determined 10 yr earlier. The mean clutch size of Ross' Geese was greater in island habitats where nest densities were high than in less populated island or mainland habitats. The average size of Snow Goose clutches did not differ significantly among island habitats but was larger at island than at mainland sites. Large clutches were most likely attributable to older and/or earlier nesting females. Habitat preferences apparently differed between species. Small clutches presumably indicated that young geese nested in areas where nest densities were low. The establishment of mainland nesting at Karrak Lake probably began with young Snow Geese using peripheral areas of the colony. Young Ross' Geese nested in sparsely populated habitats on islands to a greater extent than did Snow Geese. Ross' Geese also nested on the mainland but in lower densities than Ross' Geese nesting in similar island habitats. Successful nests with the larger clutches had closer conspecific neighbors than did successful nests with smaller clutches. The species composition of nearest neighbors changed significantly with distance from Snow Goose nests but not Ross' Goose nests. Nesting success was not affected by the species of nearest neighbor, however. Because they have complementary antipredator adaptations, Ross' and Snow geese may benefit by nesting together.

LATTICE DYNAMICS OF THE BINARY APERIODIC CHAINS OF ATOMS I: FRACTAL DIMENSION OF PHONON SPECTRA

1995 ◽  
Vol 09 (12) ◽  
pp. 1429-1451 ◽  
Author(s):  
WŁODZIMIERZ SALEJDA
Keyword(s):  
Fractal Dimension ◽  
Lattice Dynamics ◽  
Nearest Neighbor ◽  
Average Distance ◽  
Local Maximum ◽  
Fractal Dimensions ◽  
Dimension Formula ◽  
Phonon Spectra ◽  
Wide Range ◽  
Silver Mean

The microscopic harmonic model of lattice dynamics of the binary chains of atoms is formulated and studied numerically. The dependence of spring constants of the nearest-neighbor (NN) interactions on the average distance between atoms are taken into account. The covering fractal dimensions [Formula: see text] of the Cantor-set-like phonon spec-tra (PS) of generalized Fibonacci and non-Fibonaccian aperiodic chains containing of 16384≤N≤33461 atoms are determined numerically. The dependence of [Formula: see text] on the strength Q of NN interactions and on R=mH/mL, where mH and mL denotes the mass of heavy and light atoms, respectively, are calculated for a wide range of Q and R. In particular we found: (1) The fractal dimension [Formula: see text] of the PS for the so-called goldenmean, silver-mean, bronze-mean, dodecagonal and Severin chain shows a local maximum at increasing magnitude of Q and R>1; (2) At sufficiently large Q we observe power-like diminishing of [Formula: see text] i.e. [Formula: see text], where α=−0.14±0.02 and α=−0.10±0.02 for the above specified chains and so-called octagonal, copper-mean, nickel-mean, Thue-Morse, Rudin-Shapiro chain, respectively.

Comparative analysis of breast cancer detection in mammograms and thermograms

2015 ◽  
Vol 60 (1) ◽  
Author(s):  
Marina Milosevic ◽  
Dragan Jankovic ◽  
Aleksandar Peulic
Keyword(s):  
Nearest Neighbor ◽  
Region Of Interest ◽  
Texture Features ◽  
Classification Performance ◽  
Support Vector ◽  
K Nearest Neighbor ◽  
Characteristic Analysis ◽  
Analysis Society ◽  
Fold Cross Validation ◽  
Neighbor Classifier

AbstractIn this paper, we present a system based on feature extraction techniques for detecting abnormal patterns in digital mammograms and thermograms. A comparative study of texture-analysis methods is performed for three image groups: mammograms from the Mammographic Image Analysis Society mammographic database; digital mammograms from the local database; and thermography images of the breast. Also, we present a procedure for the automatic separation of the breast region from the mammograms. Computed features based on gray-level co-occurrence matrices are used to evaluate the effectiveness of textural information possessed by mass regions. A total of 20 texture features are extracted from the region of interest. The ability of feature set in differentiating abnormal from normal tissue is investigated using a support vector machine classifier, Naive Bayes classifier and K-Nearest Neighbor classifier. To evaluate the classification performance, five-fold cross-validation method and receiver operating characteristic analysis was performed.

Mutual Passivation in Dilute GaNxAs1-x Alloys

2005 ◽  
Vol 864 ◽  
Author(s):  
K. M. Yu ◽  
W. Walukiewicz ◽  
J. Wu ◽  
D. E. Mars ◽  
M. A. Scarpulla ◽  
...  
Keyword(s):  
Nearest Neighbor ◽  
Diffusion Length ◽  
Average Distance ◽  
Alloy System ◽  
Group Iv ◽  
Semiconductor Alloys ◽  
Drastic Reduction ◽  
Free Electron Concentration ◽  
Ternary Semiconductor ◽  
Good Agreement

AbstractThe dilute GaNxAs1-x alloys (with x up to 0.05) have exhibited many unusual properties as compared to the conventional binary and ternary semiconductor alloys. We report on a new effect in the GaNxAs1-x alloy system in which electrically active substitutional group IV donors and isoelectronic N atoms passivate each other's activity. This mutual passivation occurs in dilute GaNxAs1-x doped with group IV donors through the formation of nearest neighbor IVGa- NAs pairs when the samples are annealed under conditions such that the diffusion length of the donors is greater than or equal to the average distance between donor and N atoms. The passivation of the shallow donors and the NAs atoms is manifested in a drastic reduction in the free electron concentration and, simultaneously, an increase in the fundamental bandgap. This mutual passivation effect is demonstrated in both Si and Ge doped GaNxAs1-x alloys. Analytical calculations of the passivation process based on Ga vacancy mediated diffusion show good agreement with the experimental results.

scholarly journals Dynamic Scheduling Model of Bike-Sharing considering Invalid Demand

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Liu He ◽  
Tangyi Guo ◽  
Kun Tang
Keyword(s):  
Optimization Model ◽  
Dynamic Scheduling ◽  
Demand Forecasting ◽  
Optimal Solution ◽  
Coupling Model ◽  
Service Level ◽  
Demand Prediction ◽  
Dynamic Relationship ◽  
Proposed Model ◽  
Bike Sharing

System resources allocation optimization through dynamic scheduling is key to improving the service level of bike-sharing. This study innovatively introduces three types of invalid demand with negative effect including waiting, transfer, and abandoning, which consists of the total demand of bike-sharing system. Through exploring the dynamic relationship among users’ travel demands, the quantity and capacity of bikes at the rental points, the records of bicycles borrowed and returned, and the vehicle scheduling schemes, a demand forecasting model for bike-sharing is established. According to the predicted bikes and the maximum capacity limit at each rental point, an optimization model of scheduling scheme is proposed to reduce the invalid demand and the total scheduling time. A two-layer dynamic coupling model with iterative feedback is obtained by combining the demand prediction model and scheduling optimization model and is then solved by Nicked Pareto Genetic Algorithm (NPGA). The proposed model is applied to a case study and the optimal solution set and corresponding Pareto front are obtained. The invalid demand is greatly reduced from 1094 to 26 by an effective scheduling of 3 rounds and 96 minutes. Empirical results show that the proposed model is able to optimize the resource allocation of bike-sharing, significantly reduce the invalid demand caused by the absence of bikes at the rental point such as waiting in a place, walking to other rental points, and giving up for other travel modes, and effectively improve the system service level.

scholarly journals Leveraging Integrated Bike-Sharing with Existing Bus Rapid Transit (BRT) to Reduce Motor Vehicle in Central Jakarta Municipal

2019 ◽  
Vol 6 (1) ◽  
pp. 13
Author(s):  
Daniella Daniella ◽  
Achmad Amri Dharma Wangsa
Keyword(s):  
Public Transportation ◽  
Motor Vehicle ◽  
Motor Vehicles ◽  
Walking Distance ◽  
Bus Rapid Transit ◽  
Rapid Transit ◽  
Transportation Mode ◽  
Smart Transportation ◽  
Bike Sharing ◽  
The Government

Jakarta is one of the most congested cities in the world due to a plethora of motor vehicles used in the city. One of the government actions to address the issue is by implementing Bus Rapid Transit (BRT) as an alternative public transportation mode. However, according to the convenience walking distance standard, the BRT coverage the inhabitant to choose motor vehicle rather than walking. This paper purposes Bike-Sharing as the smart transportation mode to overcome such issue and predict the three potential places to establish sharing-bike stations according to the convenience walking distance standard. In this paper the walking distance is classified into 100 mater range (300 meter, 400 meter and 500 meter) projected using the euclidean distance principle. As the result for 300 meter standard, there are 809 potential bike-sharing stations consist of 164 main stations and 645 feeder stations, while the 400 meter standard needs 541 potential stations with 140 stations serve the BRT station directly and 401 stations as the feeder. Furthemore, with 500 meter standard, 359 stations consist of 131 main stations and 228 feeder stations is needed.

scholarly journals Traffic Safety Perception, Attitude, and Feeder Mode Choice of Metro Commute: Evidence from Shenzhen

2020 ◽  
Vol 17 (24) ◽  
pp. 9402
Author(s):  
Yuanyuan Guo ◽  
Linchuan Yang ◽  
Wenke Huang ◽  
Yi Guo
Keyword(s):  
Traffic Safety ◽  
Mode Choice ◽  
Urban Transport ◽  
Travel Mode ◽  
Metro Station ◽  
Face To Face ◽  
Positive Attitudes ◽  
Last Mile ◽  
Safety Perception ◽  
Bike Sharing

Like many other transit modes, the metro provides stop-to-stop services rather than door-to-door services, so its use undeniably involves first- and last-mile issues. Understanding the determinants of the first- and last-mile mode choice is essential. Existing literature, however, mostly overlooks the mode choice effects of traffic safety perception and attitudes toward the mode. To this end, based on a face-to-face questionnaire survey in Shenzhen, China, this study uses the two-sample t-test to confirm the systematic differences in traffic safety perception and attitudes between different subgroups and develops a series of multinomial logistic (MNL) models to identify the determinants of first- and last-mile mode choice for metro commuters. The results of this study show that: (1) Walking is the most frequently used travel mode, followed by dockless bike-sharing (DBS) and buses; (2) Variances in traffic safety perception and attitude exist across gender and location; (3) Vehicle-related crash risks discourage metro commuters from walking to/from the metro station but encourage them to use DBS and buses as feeder modes; (4) DBS–metro integration is encouraged by the attitude that DBS is quicker than buses and walking, and positive attitudes toward the bus and DBS availability are decisive for the bus–metro and DBS–metro integration, respectively; and (5) Substantial differences exist in the mode choice effects of traffic safety perception and attitudes for access and egress trips. This study provides a valuable reference for metro commuters’ first- and last-mile travel mode choice, contributing to developing a sustainable urban transport system.

Satisfaction with telemedicine for teaching listening and spoken language to children with hearing loss

2012 ◽  
Vol 18 (5) ◽  
pp. 267-272 ◽  
Author(s):  
Gabriella Constantinescu
Keyword(s):  
Hearing Loss ◽  
Average Distance ◽  
Video Quality ◽  
Spoken Language ◽  
Telemedicine Service ◽  
Face To Face ◽  
High Satisfaction ◽  
Rural And Remote Areas ◽  
Children With Hearing Loss ◽  
Auditory Verbal Therapy

Auditory-Verbal Therapy (AVT) is an effective early intervention for children with hearing loss. The Hear and Say Centre in Brisbane offers AVT sessions to families soon after diagnosis, and about 20% of the families in Queensland participate via PC-based videoconferencing (Skype). Parent and therapist satisfaction with the telemedicine sessions was examined by questionnaire. All families had been enrolled in the telemedicine AVT programme for at least six months. Their average distance from the Hear and Say Centre was 600 km. Questionnaires were completed by 13 of the 17 parents and all five therapists. Parents and therapists generally expressed high satisfaction in the majority of the sections of the questionnaire, e.g. most rated the audio and video quality as good or excellent. All parents felt comfortable or as comfortable as face-to-face when discussing matters with the therapist online, and were satisfied or as satisfied as face-to-face with their level and their child's level of interaction/rapport with the therapist. All therapists were satisfied or very satisfied with the telemedicine AVT programme. The results demonstrate the potential of telemedicine service delivery for teaching listening and spoken language to children with hearing loss in rural and remote areas of Australia.

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